<!DOCTYPE html>
<html class="reftest-wait foo">
<title>View transitions: ensure :only-child is supported on view-transition-new</title>
<link rel="help" href="https://drafts.csswg.org/css-view-transitions-1/">
<link rel="author" href="mailto:khushalsagar@chromium.org">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
::view-transition {
  background-color: black;
}
html:only-child {
  background-color: black;
}
:root:only-child {
  background-color: black;
}
:only-child {
  background-color: black;
}
.foo:only-child {
  background-color: black;
}

::view-transition-new(root) {
  background-color: blue;
}
::view-transition-new(target) {
  background-color: blue;
}
::view-transition-new(*) {
  color: blue;
}

::view-transition-new(root):only-child {
  background-color: red;
}
::view-transition-new(target):only-child {
  background-color: red;
}
::view-transition-new(*):only-child {
  color: red;
}

</style>
<div id="target"></div>

<script>
let matchedColor = "rgb(255, 0, 0)";
let notMatchedColor = "rgb(0, 0, 255)";

promise_test(() => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  return new Promise(async (resolve, reject) => {
    document.documentElement.style.viewTransitionName = "none";
    target.style.viewTransitionName = "none";
    let transition = document.startViewTransition(() => {
      document.documentElement.style.viewTransitionName = "root";
    });

    transition.ready.then(() => {
      let style = getComputedStyle(document.documentElement, "::view-transition-new(root)");
      if (style.backgroundColor == matchedColor && style.color == matchedColor)
        resolve();
      else
        reject(style.backgroundColor + " and " + style.color);
    });
  });
}, ":only-child should match because ::view-transition-old is not generated (none to root)");

promise_test(() => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  return new Promise(async (resolve, reject) => {
    document.documentElement.style.viewTransitionName = "root";
    target.style.viewTransitionName = "none";
    let transition = document.startViewTransition();

    transition.ready.then(() => {
      let style = getComputedStyle(document.documentElement, "::view-transition-new(root)");
      if (style.backgroundColor == notMatchedColor && style.color == notMatchedColor)
        resolve();
      else
        reject(style.backgroundColor + " and " + style.color);
    });
  });
}, ":only-child should not match because ::view-transition-old is generated (root to root)");

promise_test(() => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  return new Promise(async (resolve, reject) => {
    document.documentElement.style.viewTransitionName = "none";
    target.style.viewTransitionName = "root";
    let transition = document.startViewTransition(() => {
       document.documentElement.style.viewTransitionName = "root";
       target.style.viewTransitionName = "none";
    });

    transition.ready.then(() => {
      let style = getComputedStyle(document.documentElement, "::view-transition-new(root)");
      if (style.backgroundColor == notMatchedColor && style.color == notMatchedColor)
        resolve();
      else
        reject(style.backgroundColor + " and " + style.color);
    });
  });
}, ":only-child should not match because ::view-transition-old is generated (element to root)");

promise_test(() => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  return new Promise(async (resolve, reject) => {
    target.style.viewTransitionName = "none";
    document.documentElement.style.viewTransitionName = "none";
    let transition = document.startViewTransition(() => {
      target.style.viewTransitionName = "target";
    });

    transition.ready.then(() => {
      let style = getComputedStyle(document.documentElement, "::view-transition-new(target)");
      if (style.backgroundColor == matchedColor && style.color == matchedColor)
        resolve();
      else
        reject(style.backgroundColor + " and " + style.color);
    });
  });
}, ":only-child should match because ::view-transition-old is not generated (none to element)");

promise_test(() => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  return new Promise(async (resolve, reject) => {
    target.style.viewTransitionName = "none";
    document.documentElement.style.viewTransitionName = "root";
    let transition = document.startViewTransition(() => {
      document.documentElement.style.viewTransitionName = "none";
      target.style.viewTransitionName = "element";
    });

    transition.ready.then(() => {
      let style = getComputedStyle(document.documentElement, "::view-transition-new(root)");
      if (style.backgroundColor == notMatchedColor && style.color == notMatchedColor)
        resolve();
      else
        reject(style.backgroundColor + " and " + style.color);
    });
  });
}, ":only-child should not match because ::view-transition-old is generated (root to element)");

promise_test(() => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  return new Promise(async (resolve, reject) => {
    target.style.viewTransitionName = "target";
    document.documentElement.style.viewTransitionName = "none";
    let transition = document.startViewTransition();

    transition.ready.then(() => {
      let style = getComputedStyle(document.documentElement, "::view-transition-new(target)");
      if (style.backgroundColor == notMatchedColor && style.color == notMatchedColor)
        resolve();
      else
        reject(style.backgroundColor + " and " + style.color);
    });
  });
}, ":only-child should not match because ::view-transition-old is generated (element to element)");
</script>
